Image pickup apparatuses such as a video camera and a digital still camera are used in photographing color images, and solid-state image pickup devices such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor) image sensor used in those cameras also have sensitivities with respect to a wavelength band from a rear-ultraviolet wavelength band to a near-infrared wavelength band.
In photographing color images, however, optical signals of wavelength bands excluding that corresponding to a visibility of human beings (wavelength of about 400 to 700 nm) become noise components with respect to correct color images when observations are made by human beings. In this regard, for obtaining correct color images, there is a need to detect signals from which light of a near-infrared wavelength band has been removed, by providing an infrared cut filter in a photoelectric conversion device of the solid-state image pickup device.
The infrared cut filter is generally provided between an image pickup optical system and the solid-state image pickup device, and an absorption-type infrared cut filler formed of a material that absorbs the infrared band or a reflection-type infrared cut filter that uses an interference of a multilayer film is used.
Incidentally, in recent years, while miniaturization of image pickup apparatuses is progressing, the infrared cut filter generally has a thickness of about 1 to 3 mm, and the thickness of the infrared cut filter is becoming a problem in the point of thinning of a digital camera. Particularly in a camera module equipped in a cellular phone, a mobile terminal apparatus, and fee like, thinning of an image pickup optical system is essential. In addition, since there is a need to mount the infrared cut filter in the image pickup apparatus together with the solid-state image pickup device, improvements are desired also in the point of production costs of the image pickup apparatus.
Here, Patent Document 1 discloses a solid-state image pickup device in which a flattening layer and on-chip lens having an infrared absorption ability are laminated on a photoelectric conversion device. Since the flattening film and on-chip lens have an infrared absorption ability, the infrared cut filter does not need to be provided in addition to the solid-state image pickup device, thus enabling the image pickup optical system to be thinned.
Further, Patent Document 2 discloses a solid-state image pickup device that removes infrared components by a color filter to which an infrared absorption material is added, the color filter being arranged on a photoelectric conversion device. This solid-state image pickup device also does not need to additionally include an infrared cut filter, thus enabling the image pickup optical system to be thinned.
Patent Document 1: Japanese Patent Application Laid-open No. 2004-200360
Patent Document 2: Japanese Patent Application Laid-open No. 2007-141876